I confess I celebrated my last chemo, but many feel as you do. Treatment is reassuring - difficult sometimes, but also a regular, known event in an uncertain environment. I too had another nine months of herceptin after chemo, which I had by infusion rather than injection so back to the familiar routine every three weeks. I am on letrozole not tamoxifen but, as with chemo, side effects do vary a lot so it’s almost impossible to know how you will find it until you start. If possible, try not to make assumptions before you start. Letrozole can cause a lot of joint pain. I don’t have any, nearly seven years on. If you do get difficult side effects, talk about it with your oncologist and see what options can be explored. Best wishes.